When text is displayed in newspaper columns the length of each line is much shorter. This is a great aid to readability. On the internet many people will skim read large blocks of text and this can have the unfortunate effect that they miss important points buried in a long paragraph.

(CSS 3) Browser Support: IE 10, Opera. Use the equivalent -moz-column-rule for Firefox and -webkit-column-rule for Safari and Chrome.

“I don't want anyone reading my writing to think about style. I just want them to be in the story” ~ Willa Sibert Cather